Hi Everyone,
I went through the SPI by Aidan. It’s pretty straightforward.
One question I have is whether there is a recommended protocol for handling/ returning data from the Slave side of things?
Any thoughts?
Gerard
Hey @Gerard163258!
From what I gather SPI device functionality is not baked directly into the Arduino Libraries. However, you can implement a basic SPI device by reading data directly out of the SPI data register. A simple example is documented in this Stack Exchange thread.
If you’re not married to the idea of SPI specifically and just want to play around with making a smart device, we’ve covered setting up an Arduino as an I2C device before in this episode of The Factory.
This shows how we create a complex device that can be written to and read from. In this case we can issue commands to the I2C module (a buzzer) to play a tone, for a specified duration. The working source code is in the GitHub repo (both the Arduino Code for the I2C responder, and the Python driver for the I2C Initiator).
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Thanks Michael,
That does complicate things a bit. In my comms protocol between Master and Slave, the data traffic is pretty light on so I could go with SPI.
I also did testing with I2C but made the SPI choice as it seemed more simple at the time. I could redo the PCB to go I2C.
Actually, I’m debating whether to just make my Master device a Pi rather than an Atmega328 (Arduino). Probably a tad more expensive with the Pi but then I don’t need to worry about a LAN connection plus a few other things with the Atmega CPU.
PCB fab is so quick and cheap these days (I use NextPCB) that it’s easy to redo a PCB.
Gerard
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